This invention relates to nucleic acid extraction methods.
A nucleic acid hybridization assay typically is performed on nucleic acids that have been isolated from cells. A common method of carrying out the isolation is the phenol extraction method.
Lizardi et al., 98 Analytical Biochem. 116 (1979), describe a method for extracting RNA from cells. The method includes the steps of treating a cell sample with, consecutively, a solution containing sodium dodecyl sulfate (SDS) and proteinase K; aqueous sodium perchlorate; and ethanolic perchlorate. The cell samples used by Lizardi et al. include homogenized posterior silk glands from larvae, homogenized dog pancreas, homogenized spinach leaves, and concentrated tissue culture cells.
Lizardi et al.'s method is a modification of the procedure described by Wilcockson, 66 Analytical Biochem, 64 (1975). In the abstract on page 64, Wilcockson says that "[t]he addition of an appropriate mixture of ethanol, water and sodium perchlorate to crude extracts of some biological material results in the selective precipitation of nucleic acids."
Wilcockson, 135 Biochem. J. 559 (1973), describes using sodium perchlorate for deproteinization during the extraction of nucleic acid from cells.